Stopper assembly



Dec. 5, 1961 J. R. DREVER sToPPER ASSEMBLY Filed Dec. 12, 1957 1 INVENTOR.

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UnitedStates Patent D ice 3,011,231 STOPPER ASSEMBLY v.lames Ross Drever, Geneva, Ill., assignor to Griiiin Wheel Company, Chicago, Ill., a corporation of Delaware l Filed Dec. 1,2, 1957, Ser. No. 702,435

. 1 Claim. (Cl. 22'-85) This invention relates to casting apparatus and more flow of metal therethrough after the mold cavity has been filled.

In apparatus of this type, the stopper assembly has consisted of a stopper with a tapered seat connected to a hollow shaft or pipe utilized to support the stopper and to urge the latter against the mold seat when the mold has been filled. In a casting of high melting point metal, such as steel, the pipe or shaft has sometimes melted or burned through from the heat of the molten metal in the mold, particularly at a point immediately above the stopper where the molten metal is at the highest temperature when the gate is closed by the stopper.

Such damage to the stopper shaft or pipe is undesirable due to the possibility that pressure exerted against the stopper by the pipe may be released with consequential loss of molten metal from the gate. Also, the solidified casting is generally removed from the mold by a hoist or other lifting mechanism which may be conveniently attached to the stopper, and this practice might involve accidental dropping of the casting if the stopper pipe is burned through as above described so that it may slip through the hole in the casting above the point where the stopper has burned through.

lAnother problem involved in prior art stopper assemblies has been the diiculty of ensuring proper mating of the stopper seat with the mold seat around the gate.

Accordingly, a primary object of the present invention is to prevent destruction of the stopper shaft or pipe by molten steel or other high melting point metal Within the mold.

Another object of the invention'is to afford a flexible connection between the stopper and the pipe so that the seat on the' stopper will automatically align with the mating seat of the mold as the stopper is urged to closed position under pressure against the mold seat.

A more specific object of the invention is to devise a simple and economical insulation around the pipe at and above its connection to the stopper. According to the invention it has been discovered that this may be effectively accomplished by a section of ordinary black iron pipe having one end in fluid-tight engagement with the stopper and having its other end connected, as by welding, to the pipe or hollow shaft upon which thev stopper is mounted. The fit between the two pipes is snug but not air-tight so that a minute air space is provided between the two pipes and has been found to afford the necessary insulation against destruction of the inner pipe by the heat of molten steel or other high melting point metals in the mold.

Yet another object of the invention is to devise a simple economical and effective flexible connection between the stopper and the pipe which actuates it to closed po- 3,011,231 Patented Dec. 5, 1961'y sition. According to the invention this has been accomplished by providing a plurality of cuts or slots in one end of the pipe dividing it into a plurality of segments preferably three or more in number. The segments are press fitted within a complementary aperture or socket of the stopper. This fit is a force fit which is suiiiciently tight to hold the stopper and its pipe in assembled relationship under all normal operating conditions, but affords suticient flexibility so that the stopper seat will be automatically aligned with and in liquid-tight mating relationship with the engaged mold seat despite normal manufracturing variations in the mold -and stopper as sembly. .v l

v The foregoingand` other objects and advantages of the invention will become apparent from the following specication and the accompanying drawings, wherein:

FIGURE 1 is a fragmentary central vertical sectional view of casting apparatus having embodied therein a preferred form of the novel stopper assembly; i

FIGURE 2 is a fragmentary side elevational view of the slotted end of the pipe with the insulator sleeve thereon, and

FIGURE 3 is a bottom plan view of the pipe taken from its slotted end.

Describing the invention in detail and referring to the drawings, it will be seen that the novel stopper rod assembly comprises a pipe or hollow shaft 2. preferably round in cross section as seen in FIGURE 3. The pipe 2 is slidably fitted within complementary guide openings of a sand dome 4 and a chill ring 6 mounted in the dome as more fully described in said copending application. The dome is mounted within an opening of a permanent mold fragmentarily shown at 8 in FIGURE 1. The construction and function of the dome 4 and chill ring 6 are more fully described in said copending application and are not per se part of the present invention.

One end of the pipe 2 is slotted as at 9 to provide a plurality of segments which are press fitted within a complementary aperture or socket of a stopper 10 having a downwardly tapering conical seat 12 adapted to mate with a complementary seat (not shown) of the mold when the pipe 2 is urged downwardly to close the mold gateas heretofore described.

A sleeve 14 is snugly telescoped on the pipe 2 as best seen in FIGURE l, and it may be emphasized that the fit between the sleeve and pipe is not air-tight so that a small layer of air is enclosed in the space 16.between the sleeve 14 landthe pipe 2 which are preferably interconnected, as by welding, at 18; The -air in space 16 functions as an insulator andphas been found to eliminate the prior art difficulty ofburned stopper pipes 2 as heretofore described. The bottom edge of the sleeve 14 is perpendicular to its longitudinal axis and that of the pipe 2 and is finished smooth and flat to engage a complementary smooth flat top surface of the stopper 10 in substantially liquid-tight engagement so that'the air in the space 16 is confined between the stopper 10 and the weld 18. Thus, the molten steel cannot contact the pipe 2 below the lower end of the sleeve 14.

It may be noted that under normal operating conditions theVsleeve 14 may be burned or melted through, but not until the molten steel within the mold has cooled suiciently to prevent melting or burning of the pipe 2. In this connection it may be noted that the sleeve 14 is preferably shorter than the pipe 2 inasmuch as insulation is normally needed only adjacent the lower end of the pipe 2 where the molten steel is at its highest temperature within the mold cavity. However, if desired, the sleeve 14 may be longer or shorter than that illustrated in FIGURE 1 and may extend for the full length of the pipe 2. Also, if desired, a second sleeve may be telescoped on the sleeve 14 and'attached thereto or to the pipe 2, as by welding, if a second insulating layer of air is desired around the pipe 2.

It may be emphasized that if the seat 12 of the stopper 10 is urged to closed Y position with respect to a complementary seat (not shown) of the mold, lthe slotted end of the pipe 2 within the socket of the stopper 10 is suciently exible to accommodate slight misalignment of the seats so that the stopper seat 12 is angled to automatically align with the mold seat as the stopper is urged to closedv position in mating engagement with the mold seat. Thus, the slotted end of the pipe 9 functions as a simple economicaland effective ball-point connection between the stopper 10 and the pipe 2.

I claim:

In a stopper assembly for closing the gate of a mold, the combination of an elongated member having a slotted end, a stopper'press-litted on said end-and having a seat to engage a mold seat around said gate, a sleeve 4 f l spatially' mounted on and sealed at one end to said member and in abutment with said stopper at the other end, the space between the sleeve and member containing air serving as an insulator.

References Cited in the le of this patent UNITED STATES PATENTS 2,005,311 2,052,448 Coleart Aug. 25, 1936 2,080,698 yClark May 18, 1937 2,210,158 Avakian Aug. 6, 1940 2,248,941 Bidner et al July 15, 1941 2,336,518 Whittaker Dec. 14,1943 2,640,630 Genco lune 2, 1953 2,792,606 Sylvester May 21, 1957 FOREIGN PATENTS 930,162 France July 28, 1947 Belding June 18 1935 

